1. Field of the Invention
The present invention relates to a total hip prostheses adapted to be implanted endo-articularly and its auxiliary device. Upon deterioration of the articulation of the hip, for example in the case of arthrosis or rheumatoid arthritis, it may be necessary to replace the coxo-femoral articulation by a prosthesis.
2. Description of the Related Art
Certain prostheses now known comprise:
a cotyloid implant constituted by a metallic cup provided with primary anchoring means in the acetabulum and having externally an overall hemispheric surface and internally a concave recess, PA1 an insert forming an intermediate implant generally of plastic, such as polyethylene, provided with means for connection with the cup and having externally a surface complementary to that of the recess of the cup in which it is received and internally a substantially hemispherical recess, and PA1 a metallic femoral implant constituted by a femoral rod implanted in the medullar channel of the femur and a prosthetic neck surmounted by a spherical femoral head which will be articulated in the recess of the insert. PA1 an insert forming an intermediate implant for example of a plastic such as polyethylene, provided with connection means with the cup and having externally a shape complementary to the recess of the cup in which it is received and internally a concave bearing recess, and PA1 a metallic femoral implant adapted to be received slidably in the bearing recess of the insert and implanted ill the femoral bone, PA1 characterized in that the femoral implant is constituted by a cap having externally a convex surface adapted to come into sliding bearing engagement in the recess of the insert and internally a concave surface adapted to implant itself in the spongy bone of the femoral head. PA1 a plurality of instruments adapted to be introduced along the axis of the femoral neck from the region of the trochanter base toward the coxo-femoral articular space such that their free distal end serves to center and guide the prosthesis during its implantation, PA1 a carrying arm that can support removably at its distal end the mentioned implants or a drill for introducing them by a lateral access route in the mentioned articular space, and PA1 a support structure adapted to be positioned parallel to the axis of the femur and at the lower end of which is selectively ensleeved or introduced freely in rotation and/or slidably one of the mentioned instruments and at the upper end of which is ensleeved the carrying arm slidably and inclinably to engage the implant or the drill on the distal end of an instrument opening into the articular space.
Implanting such a prosthesis requires an expensive total arthroplasty technique of the hip, which is subject to a number of requirements.
Thus, it is necessary to provide an ablation of the femoral head and a portion of the femoral neck to implant the femoral rod in the midportion of the femur, even if the degeneration of the articulation hasn't reached the neck or head of the femur.
In addition to ablation of the head of the femur, it is necessary to do the same for all of the articular capsule.
On the other hand, in this open surgery, it is necessary to provide access of about ten centimeters and to dislocate the articulation to be able to introduce the various instruments for cutting and the various implants.